WO2003018704A1

WO2003018704A1 - Moisture cross-linking elastic composition

Info

Publication number: WO2003018704A1
Application number: PCT/EP2002/007126
Authority: WO
Inventors: Wolfram Schindler; Oliver SCHÄFER; Martina Chatzinerantzis; Bernd Pachaly
Original assignee: Consortium für elektrochemische Industrie GmbH
Priority date: 2001-08-23
Filing date: 2002-06-27
Publication date: 2003-03-06
Also published as: JP2005501165A; DE10141235A1; US7026425B2; EP1419208B1; DE50201697D1; US20040260037A1; EP1419208A1

Abstract

The invention relates to moisture cross-linking compositions containing (A) 100 parts per weight of a silane-terminated polydiorganosiloxane-urea/urethane copolymer of general formula (1), and (B) between 0.1 and 20 parts per weight of silane of general formula (3): Φ-(CH2)e-Si(R2)3-f(CH3)f, in which R, X, A, Y, D, B, W, n, a, b, c, d, Φ, R2, e and f are defined as per claim 1.

Description

Moisture-curing elastic composition

The invention relates to a one-component ^'e, reactive, moisture-composition based on polydimethylsiloxane urea / urethane copolymers with alkoxysilane end groups and their use as hot melt adhesive.

Hot melt adhesives are generally physically setting adhesives that are present in one component at room temperature in a solid, essentially solvent-free form. Following the Anglo-Saxon language use, these are. also called "hotmelts".

The polymer components or binders such hot melt adhesives have a predominantly linear chain-like ^'"structure and are located at room temperature in an amorphous, glass-like or partially crystalline state. To achieve and achieve other specific properties such as Kohesionsfestigkeit, viscosity, softening point or setting rate can further in the adhesive formulation These include tackifying resins to improve the wetting properties and increase the adhesion, plasticizers to increase the flexibility and decrease "melt viscosity, stabilizers and antioxidants to reduce the oxidative change during processing of the melt under the influence of oxygen, and to improve the Aging behavior of the glued joint. Fillers can also be used to increase strength and, if necessary, to reduce costs. The most important hot melt adhesives are based on binder systems such as polyurethanes, epoxy resins, polyamides, ethylene-vinyl acetate copolymers, styrene block copolymers, saturated polyesters, polyols in copolymers, synthetic rubbers and mixtures of these systems.

While the amorphous. Soften polymers over a more or less wide temperature range, the crystalline or semi-crystalline show a more or less sharp Melting point. Amorphous systems of copolyesters, for example, often show a cold flow that is still present, even with high molar masses, and are therefore only of limited use or can only be used in combination with very high molecular weight copolymers.

One way to increase the cohesive strength and heat resistance (adhesive properties even at higher service temperatures) of hot melt adhesives is to use reactive adhesives. Such reactive formulations are known as a special form of hotmelts, which represent a combination of physically setting and chemically reacting systems. For this purpose, hydroxy-functional polyesters are generally reacted with an excess of diisocyanates and isocyanate-terminated polymers are produced therefrom. These can ^" harden when cross-linking occurs when air humidity is present. ^' Because the polyurethane hotmelts have several weaknesses due to the system, such as isocyanate monomer emission (monomeric aromatic diisocyanates such as MDI or TDI, or their corresponding amines are suspected of being carcinogenic), CO2 elimination which leads to the formation of bubbles or which

Many systems based on silane-crosslinking polymers are also currently being developed, which represent a promising alternative with regard to the disadvantages mentioned above. The prepolymers are reacted with silane-functional monomers, so that it is also possible to produce hot-melt adhesives that crosslink with moisture.

To simplify processing, one-component systems are preferred because they are easier to apply and to automate. Since in the case of reactive hot-melt adhesives, the rate of hardening of such one-component compositions is usually set moderately to ensure adequate storage stability, the variation of the property profile is more difficult. On the other hand, problems with non-post-crosslinking systems are usually the heat resistance (cold flow, re-meltable), the mechanical properties and adhesion to the surface. These disadvantages are largely avoided with the moisture-curing systems described above. Two-component compositions usually have a significantly better property profile, but are problematic in terms of processing. The mixture of the components, for example using a static mixer in the application, must be uniform to ensure a constant processing time and final quality. Usually a compromise has to be made between curing time and processing time. The equipment required for two-component adhesives is also significantly greater and the application is therefore usually more expensive.

Organosiloxane copolymers, especially polydiorganosiloxane-urethane and polydiorganosiloxane-urea copolymers, are known. The ^"' ; ^" different systems are in the overview ΛTOΏ. I. Yilgör and ^" JE McGrath in Adv. Poly. Sei., 1988, 86, pp. 1-86. A large number of further publications and patents deal with special applications of such block copolymers. Polyurethanes and silicone elastomers are complementary in a wide range. The combination of both systems therefore provides materials with novel, excellent properties. Polyurethanes are characterized by their good mechanical strength, elasticity and very good adhesion and abrasion resistance. Silicon elastomers, on the other hand, have excellent temperature, UV, weathering stability and special surface properties (low surface tension) They retain their elastic properties at lower temperatures and therefore do not tend to become brittle.

In the overview by I. Yilgör et al. in Polymer, 1984 (25), pp. 1800-1816, the properties of polydiorganosiloxane-urea copolymers are examined in more detail. The silicone and isocyanate polymer building blocks can be mixed in a wide range without problems. The mechanical properties are determined by the ratio of the different polymer blocks. The polydiorganosiloxanes form the so-called soft segments and are decisive for the elasticity, the diisocyanates form the hard segments and are decisive for the mechanical properties. The mechanical properties are determined by forming hydrogen bonds between urethane or urea binding groups. Due to the strong interactions of the hydrogen bonds between the urea units, these masses are usually very highly viscous or solid at room temperature.

A large number of applications and possible uses are described and discussed in the overviews mentioned above. In EP-A-250248 and the production of a possible application of these ^copolymers' for non-stick coatings and pressure-sensitive adhesives is described. WO 96/34030 also describes a possible production of polysiloxane-urea copolymers with reactive and non-reactive end groups. Alkoxysilanes, among other things, are used as reactive end groups to terminate the polymers.

The present invention relates to moisture-crosslinkable compositions containing (A) 100 parts by weight of silane-terminated polydiorganosiloxane urea / urethane copolymer of the general formula 1

R R W

I

-O-D- O- -C-N-Y-N-C- -A- X- -Si- -Si -X-A- C-N-Y-N- C-N-B

I I H H II I 1 II H H II o o R R O o

( 1 ) , wherein

R is a monovalent hydrocarbon radical with 1 to 20, optionally substituted by fluorine or chlorine

Carbon atoms, X is an alkylene radical with 1 to 20 carbon atoms, in which methylene units are not adjacent by groups

-0- ^' may be replaced, A is an oxygen atom or an amino group -NR ^X -, R ^{x is} hydrogen or an alkyl radical having 1 to 10

Carbon atoms, Y one optionally substituted by fluorine or chlorine

Hydrocarbon radical with 1 to 20 carbon atoms, D one optionally by fluorine, chlorine, Ci-Cg-alkyl or

C ^ -Cg alkyl ester substituted alkylene radical with 1 to 700. ^' - carbon atoms, in which non-adjacent methylene units can be replaced by groups -0-, -C00-, -0C0-, or - OCOO-, B is a radical of general formula 2

-Z- ^S i ⁽ R ^l) _m ⁽ R- ⁾ ₃ -m (2),

Z is an alkylene radical with 1 to 10 carbon atoms,

R! a monovalent hydrocarbon radical with 1 to 12 carbon atoms, optionally substituted by fluorine or chlorine,

R ^Λ * a moisture-reactive radical which is selected from C ^ -Ci-alkoxy, C_-C ₂ o ^-Ac yl ~ f Ci-Cg-alkylaminooxy- and

C] _- Cg-Alkyloximoresten,

W is a radical B or hydrogen, m is 0, 1 or 2, n is an integer from 1 to 300, a is an integer from at least 1, b is 0 or an integer from 1 to 30, c is an integer from 1 to 30 and d are 0 or 1, with the proviso that the composition of the units is selected such that the copolymer has a melting point in the range from 30 to 200 ° C. and (B) 0.1 to 20 parts by weight of silane of the general formula 3

Ω- (CH ₂ ) _e -Si (R ² ) 3-f (CH ₃ ) f (3)

in which

Ω a group selected from -NHR ³ ,

-NR ³ - (CH ₂ ) _g -NHR ³ , acrylic, methacrylic, OCN, -SH, ^" glycidoxy or chlorine residue,

R ^{3 is} hydrogen or an optionally halogen-substituted Cι_1. ₈ -hydrocarbon residue,

R ^{2 is} a methoxy or ethoxy group, e is 1 or 3 f is 0 or 1 and g is 1 to 10.

The compositions based on polydimethylsiloxane-urea / urethane copolymers can be used very well as one-component, reactive hot melt adhesives which crosslink with moisture via silane end groups. Copolymer (A) is in the hot melt adhesive. Binder and silane (B) act as an adhesion promoter. The suitable choice of the polymer building blocks in the production of the silane-terminated copolymers makes hot melt adhesives accessible which are distinguished by excellent mechanical properties and very good adhesion properties. Furthermore, the application properties such as application temperature, melt viscosity and processing properties can be set within a wide range.

The hot melt adhesive is processed in the form of a one-component solid mass and therefore does not have to be additionally mixed with other components at a higher temperature before application. After hot application, the hot melt adhesive forms an elastic pre-consolidated material after cooling. By The adhesive cures access to atmospheric moisture to form a network via silane condensation. Due to the high mechanical strength and the ^'good adhesion properties on the silane end of the hot-melt adhesive can be used for a wide range of elastic connections of moldings used.

R is preferably a monovalent hydrocarbon radical, preferably an alkyl radical having 1 to 6 carbon atoms, in particular unsubstituted. Particularly preferred radicals R are methyl and phenyl.

X is preferably an alkylene radical having 2 to 10 carbon atoms. The alkylene radical X is preferably not interrupted. X is particularly preferably an n-propyl radical. ^''"

Preferably A represents an amino group, i.e. Polysiloxane-urea copolymers are preferred.

R ^{1 is} preferably hydrogen or an alkyl radical having 1 to 3 carbon atoms, in particular hydrogen.

Y is preferably a hydrocarbon radical having 3 to 13, in particular 6, carbon atoms, which is preferably not substituted.

D is preferably an alkylene radical having 2 to 20, in particular 10, carbon atoms, and a radical with four carbon atoms is particularly preferred. D also preferably denotes a polyoxyalkylene radical, in particular polyoxyethylene radical or polyoxypropylene radical having at least 10 at most 200 carbon atoms.

Z is preferably an alkylene radical having 1 to 6 carbon atoms, in particular methylene and propylene. ^ is preferably an unsubstituted hydrocarbon radical having 1 to 4 carbon atoms, especially methyl.

R ^{Λ is} preferably a methoxy, ethoxy or acetoxy radical.

n preferably denotes an integer of at least 3, in particular at least 10 and preferably at most 200, in particular at most 50.

a preferably denotes an integer of at least 2, in particular at least 5 and preferably at most 50, in particular at most 20.

b is preferably an integer of at most 10,

c is preferably an integer of at least 2, and preferably at most 10.

The polydiorganosiloxane sections in the copolymer (A) preferably have a molecular weight Mw of 500 to 30,000, in particular _^ 1000 to 8000, particularly preferably 2000 to 4000.

The copolymers (A) of the general formula 1 can be prepared by reacting aminoalkyl- or hydroxyalkyl-terminated polydiorganosiloxanes of the general formula 4

with diisocyanates of the general formula 5

OCN-Y-NCO ^* (5), and silanes of the general formula 6

E [-Z-Si (R ^l ) _m (R-) ₃ > _m ] _{p (6)} ,

and if b is at least 1, additionally with α, ω-OH-terminated alkylenes of the general formula 7

HO-D-OH (7),

where R, X, A, R ", Y, D, B, Z, R ¹ , R" ^* , W, m, n, a, b, c and d have the meanings given in general formulas 1 and 2 and p the value 1,

E is an isocyanate group or an amino group -NHR ^X , where. R ^{XVΛ is} hydrogen or a monovalent hydrocarbon radical having 1 to 12 carbon atoms, optionally substituted by fluorine or chlorine, or p is 2 and

E is an -NH residue.

The polydiorganosiloxanes of the general formula 4 are preferably largely free of contamination from higher-functional and monofunctional components. Monofunctional components lead to unreactive end groups during the conversion to the polymer, which can no longer be converted by the silanes in the end termination. Non-reactive end groups lead to problems in polymer build-up during the reaction and result in products which can sometimes lead to undesired bleeding from the vulcanizate. Highly functional polydiorganosiloxanes are also undesirable since they lead to the formation of crosslinking points in the reaction with diisocyanates, which already lead to branching of the polymer chains in the polyaddition reaction. Such pre-crosslinked materials are usually unusable in terms of processing. The preparation of suitable aminoalkyl polydiorganosiloxanes is known and can be carried out, for example, as described by JJ Ho fmann, CM. Leir in Polymer Int. 1991 (24), pp. 131-138. The production of hydroxyalkyl polydiorganosiloxanes is also known, for example, via

Hydrosilylation of, ω-dihydridopolydiorganosiloxanes with α, ω-hydroxyalkylenes takes place. Such products are commercially available.

The polydiorganosiloxanes of the general formula 4 preferably have a molecular weight Mw of 500 to 30,000, in particular 1000 to 8000, particularly preferably 2000 to 4000.

The α, ω-OH-terminated alkylenes of the general formula 7 are preferably polyalkylenes or polyoxyalkylenes. For the same reasons as described for the polydiorganosiloxanes, these should be largely free of contamination from mono-, tri- or higher-functionality polyoxyalkylenes. Here, polyether polyols, polytetramethylene diols, polyester polyols, polycaprolactone diols but also α, ω-OH-terminated alkyls or polyalkylenes with two to 10 carbon atoms or based on polyvinyl acetate, polyvinyl acetate ethylene copolymers, polyvinyl chloride copolymer, polyisobutlydiols can be used. In this case, α, ω-diols such as ethanediol, butanediol or hexanediol are preferred. Such compounds are also commercially available.

In the preparation of the copolymer (A) of the general formula 1, aminoalkylpolydiorganosiloxanes of the general formula 4, in which A denotes an amino group -NR ^λ -, or hydroxyalkylpolydiorganosiloxanes of the general formula 4, in which A denotes an amino group -OH or a mixture of amino - and Hydroxyalkylpolydiorganosiloxan, with or without α, ω-OH-terminated alkylenes of the general formula 7 are used. Only aminoalkylpolydiorganosiloxane is particularly preferably used, with addition of α, ω-OH-terminated alkylenes, especially 1,4-butanediol, the mechanical properties of the vulcanizates can still be improved.

Examples of diisocyanates of the general formula 5 are aliphatic compounds such as isophorone diisocyanate, hexamethylene-1, 6-diisocyanate, tetramethylene-1, 4-diisocyanate and methylene dicyclohexy-4, 4 -diisocyanate or aromatic compounds such as methylene diphenyl-4, 4 -diisocyanate, 2, 4- toluene diisocyanate, 2, 5-toluene diisocyanate, 2,6-toluene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, m-xylene diisocyanate, tetramethyl-m-xylene diisocyanate or mixtures of these isocyanates.

The melting point of the copolymers (A) is essentially determined by the. used diisocyanate determined. The melting point of the copolymer (A) is preferably 50 to 200 ° C., in particular 60 to 150 ° C., particularly preferably 70 to. 120 ° C. In the case of pure polydiorganosiloxane-urea copolymers, the melting point of the copolymers (A) is in the range from 50-80 ° C. when using aliphatic diisocyanates to build up the polymer and can reach values of up to 200 ° C. in the case of aromatic diisocyanates Hydroxyalkylpolydimethylsiloxanes or via α, ω-OH-terminated alkylenes generally leads to a lowering of the melting point or to a broadening of the melting range.

The silanes of the general formula 6 can carry reactive groups which react with isocyanate groups. Corresponding aminosilanes are preferred here. It is also possible to use isocyanatosilanes which can be reacted appropriately with the OH and NH functions of the prepolymers. As reactive groups that harden under moisture, alkoxy groups are used in particular. In a further preferred embodiment, the copolymers (A) have silane end groups of the general formula 8

on. These can be achieved by reacting the polydiorganosiloxanes of the general formula 4 with diisocyanates of the general formula 5 with silanes of the general formula 9

Z-CH ₂ -Si ⁽ R ^l) _m ⁽ R ⁾ ₃ -m - (9)

be preserved. In general formulas 8 and 9, E,

R ^, R ^{Λ Λ} and the above meanings. E is preferably an isocyanato group, R ^{1 is} methyl, ^{XΛ is} a ^methoxy- "^" or ethoxy radical and is 0 or 1.

The silane end groups of the general formula 8 have a very high reactivity, up to a factor of 100 based on the end groups of the general formula (2), and therefore show excellent and rapid curing properties of the hot-melt adhesive under atmospheric humidity.

Examples of suitable silanes are aminopropyltriethoxysilane,

Aminopropyltrimethoxysilane, aminopropylmethyldiethoxysilane,

aminopropylmethyldimethoxysilane,

aminopropyldimethylmethoxysilane,

aminopropyldimethylethoxysilane,

Aminopropyltri (methylethylketoximo) silane,

Aminopropylmethyldi (methylethylketoximo) silane, bis-

(Triethoxysilylproyl) amine, bis (trimethoxysilylproyl) amine, aminomethyltriethoxysilane, aminomethyltrimethoxysilane, aminomethylmethyldiethoxysilane, aminomethylmethyldimethoxysilane, phenylaminopropyltrimethoxysilane, butoxaminopropyltrane

(trimethoxysilylpropyl) amine, isocyanatbpropyltriethoxysilane, isocyanatopropyltrimethoxysilane, isocyanatopropylmethyldiethoxysilane,

isocyanatopropylmethyldimethoxysilane,

isocyanatomethyltrimethoxysilane,

Isocyanatomethyltriethoxysilan,

Isocyanatomethylmethyldiethoxysilan,

Isocyanatomethylmethyldimethoxysilan,

Isocyanatomethyldimethylmethoxysilan,

Isocyanatomethyldimethylethoxysilan.

It is particularly preferred to prepare the copolymers (A) using isocyanatoalkylsilanes or secondary aminosilanes which are particularly suitable for the termination, since after the reaction of OH / NH-terminated prepolymers (obtained from the reaction of the polydiorganosiloxanes of the general formula 4 or α, ω-OH-terminated alkyls or polyalkylenes the "^'general formula 7 with diisocyanates of the general ^formula" 5 no further cross-linking reaction with the resultant of primary aminosilanes NH groups is possible. Such silane-terminated copolymers are clearly produce reproducible usually.

The preparation of copolymers (A) and the subsequent final termination can take place both in solution and in the extruder. It is essential that the ingredients are mixed optimally and homogeneously. Phase incompatibility between siloxane and polyethers can optionally be prevented by solution mediators.

To produce the copolymers (A), the components are preferably reacted in the appropriate molar ratio in a reaction extruder.

In the preparation of the copolymer (A), an NCO / OH (NH) ratio is preferably terminated via the stoichiometry of diisocyanate of the general formula 5 and OH / NH

Selected polydimethylsiloxane of the general ^"formula 4 and optionally of alkyls of the general formula 7, the 0.75 to 1.25, preferably 0.9 to 1.1, particularly preferably 0.95 to 1.05 is. The required concentration of silane of the general formula 6 is chosen such that isocyanate can no longer be detected in the finished copolymer (can be determined using standard methods such as IR spectroscopy).

For better reproducibility, the preparation should preferably take place with exclusion of moisture and under a protective gas, usually nitrogen or argon, in order to avoid premature curing by hydrolysis of the silane groups. Furthermore, the polymer building blocks used should preferably be baked out beforehand in order to remove low-molecular impurities and traces of water.

A catalyst is preferably used to prepare the copolymers (A). Suitable catalysts for the preparation are dialkyltin compounds such as ^{■ 'dibutyltin} laurate, dibutyltin diacetate, or tertiary amines - for example, N, N-dimethylcyclohexanamine, 2 - dimethylaminoethanol, 4-dimethylaminopyridine. This catalyst is also the catalyst for the silane condensation for crosslinking after the application. In the case of pure urea copolymers, the polymer can also be prepared without a catalyst, since the amine groups react spontaneously and very rapidly with the isocyanate groups. For ^■ • 'accelerate curing but a catalyst has to be introduced into the mass here. This can also be interesting for the production of catalyst-free materials, which are characterized by extremely good storage stability. In the case of very reactive silanes or for the production of rapidly crosslinking compositions, incorporation of a reactive catalyst directly before application is also conceivable.

The reaction monitoring of the copolymer (A) can be carried out using various analysis methods. The implementation is considered complete when the NCO band is no longer detectable in the infrared spectrum. The copolymers (A) are preferably prepared in a suitable solvent. In a preferred embodiment, polydiorganosiloxanes of the general formula 4 and, if appropriate, alkylenes of the general formula 7 are reacted with diisocyanates of the general formula 5 and alkoxysilanes of the general formula 6 and, if appropriate, other components are then added before the solvent is removed.

In the case of the silanes (B) likewise contained in the composition, Ω preferably means a group which is selected from a radical -NHR ³ , -NR ³ - (CH ₂ ) g -NHR ³ and glycidoxy radical.

R ³ is preferably a Cig -cyclic, linear or branched alkyl radical or a Cg_ιg aryl radical, in particular a Cj_ - _ - alkyl radical.

g is preferably 2, 3, 4 or 5.

Preferred amino functional silanes (B) are aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminopropylmethyldimethoxysilane, aminopropylmethylthiethoxysilane, aminoethyl aminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, bis-

(trimethoxysilylpropyl) amine or epoxy-functional silanes such as glycidoxypropyltrimethoxysilane, glycidoxypropyltriethoxysilane

In a further preferred embodiment, the copolymers (A) are prepared in an extruder without the addition of further solvents. In the preparation of the composition, silane (B) and optionally further additives are then incorporated into the copolymer (A) in the extruder in a second step. The extruded composition is preferably below Luf tauschluss solidified by cooling and comminuted, for example granulated ^'. To improve the adhesion properties and Oberf lächenbenetzung, the composition, especially for use as a hot melt adhesive further ^• tackifying resins, including especially silicone resins containing free OH groups or reactive alkoxy groups. Preferably, the composition contains 5-20 parts by weight of a tackifying silicone resin.

If appropriate, other silanes such as methyltrimethoxysilane or vinyltrimethoxysilanes or other conventional water scavengers can also be present.

In addition, other conventional additives can be included. Fillers such as calcium carbonate, magnesium carbonate, zinc carbonate or metal oxides such as titanium dioxide or aluminum oxide. Furthermore, reinforcing fillers such as pyrogenic or precipitated silicas and also UV absorbers. Furthermore, in the compositions for adjusting the

Processing properties include conventional plasticizers, antioxidants and pigments. Preferably, the composition contains 5-20 parts by weight of a plasticizer.

All of the above symbols of the above formulas have their meanings independently of one another. In all formulas, the silicon atom is tetravalent.

In the following examples, unless otherwise stated, all quantities and percentages are based on weight and all pressures are 0.10 MPa (abs.). The viscosities were determined on an air-bearing cone-plate rheometer (CVO 75, Bohlin). The measuring cone used has a diameter of 1 or. 2 cm with a cone angle of 1 °. It was measured with an oscillation frequency of 0-10 Hz. The viscosity at the specified temperature was determined from the slope in the shear stress-shear rate diagram. The temperature dependence of the viscosity was determined at a constant shear stress of 5000 Pa. The determination of the molecular masses was determined by means of GPC (HP1090) in toluene (0.5 ml / min) at 23 ° C; Column: PLgel Mixed C + PLgel 100 A; Detector: RI ERC7515.

Examples

Production of isocyanatomethyl-trimethoxysilane:

Starting from chloromethyltrimethoxysilane

Methylcarbamatomethyl-trimethoxysilane synthesized according to known methods (US 3,494,951).

This ^" is pumped into a quartz pyrolysis tube, which is filled with quartz wool, in an argon gas stream. The temperature in the pyrolysis tube is between 420 and 470 C. The crude product is condensed out at the end of the heated section with the aid of a cooler and collected. The colorless liquid is purified by distillation under reduced pressure and the desired product passes over 99% purity at about 88-90 C (82 mbar), while the unreacted carbamate can be reisolated in the bottom fed back to pyrolysis directly.

Starting from 56.9 g (273 mmol) of methylcarbamatomethyltrimethoxysilane, 33.9g (191 mmol) of the desired product isocyanateόmethyltrimethoxysilane are thus contained in a purity of> 97%. This corresponds to a yield of 70% of theory. Th.

Example la:

250 g (66 mmol) of α, ω-bisaminpropylpolydimethylsiloxane with an average molecular weight of 3800 are heated in a vacuum at 80 ° C. for 0.5 h, cooled to 60 ° C. and then mixed with 250 ml of dry THF. To the solution a mixture of 11.2 g (52 mmol) of isophorone diisocyanate and 6.0 g (3.1 mmol) is added isocyanatopropyltrimethoxysilane (available from CK-Witco under Silquest ^® Y-5187) rapidly. The reaction can be followed by increasing the viscosity of the solution and by means of FT-IR. The solution is stirred at 60 ° C. for a further 1 h. The implementation is complete when no more NCO bands are visible in FI-IR. The THF is then removed in vacuo. A colorless polymer with a softening range of 85-95 ° C. and a viscosity of 70 Pas at 90 ° C. is obtained. ^•

Investigation of curing behavior:

Essentially, two tests to characterize the hardening are carried out. The polymer solution in THF is mixed with 200 ppm dibutyltin dilaurate and evaporated in vacuo. a) Qualitative test to determine the melting range

100 mg of the substance applied to a glass plate (76 x 26 mm) and covered with ^"a second glass plate (at an angle of 90 °) The sandwich is heated on a hot plate at 2 ° C per minute The - of the evaporated polymer solution 50 are.. Melting is followed by shearing the two plates against each other at different temperatures. The melting process is complete when the two plates can be easily ^{'' moved} against each other. There is a continuous increase in the softening temperature from about 105 ° C. after 2 hours, to 150 ° C. after 5 hours and 240 ° C. after 24 hours. After 48 hours, melting is only possible with partial decomposition at temperatures above 250 ° C. Hardening can be significantly accelerated or slowed down by using different alkoxysilanes and amounts of catalyst. For the silane isocyanatoprσpyl-trimethoxysilane, the curing is comparably quick in all examples, only the viscosities and melting temperatures differ depending on the polymer composition. The other examples were therefore not evaluated more precisely. In the case of the silane isocyanatomethyl-trimethoxysilane, the sample can no longer be melted after only 2 hours. b) Determination of the melt viscosity

Evaporated and catalyst-mixed samples (as described above) can also be examined in the curing process by means of viscometry. The viscosity is examined depending on the temperature as a function of the curing time in air. In the present example, the viscosity increases to 15 kPas at 110 ° C. after 2 h. Production of test specimens for tensile testing: 200 ppm dibutyltin dilaurate is added to the polymer solution in THF and poured into Teflon dishes (10 x 10 cm / 5 mm layer thickness) and slowly evaporated in vacuo at 25 - 60 ° C. The test plates thus obtained are stored in air at room temperature for 14 days and then test specimens are punched out. The results of the tensile test (tensile strength, elongation at break and modulus) are summarized in Table 1.

Preparation of test pieces for adhesion test: The evaporated and admixed with 200 ppm of product described above is applied to cleaned test piece (glass, aluminum and PVC, 90 x 30 mm) from the melt and stored after cooling at Räumtermperatur ^'14 days. The liability is high by replacing tests by a ^■ - examined ^"metal spatula, the valuation is high with the following classification: Liability (+), Part Liability (0), no liability (-) The results are as shown in Table 1...

Example lb:

250 g (66 mmol) of α, ω-bisaminpropylpolydimethylsiloxane with an average molecular weight of 3800 are heated in a vacuum at 80 ° C for 0.5 h, cooled to 60 ° C and then mixed with 250 ml of dry THF. A mixture of 11.2 g (52 mmol) of isophorone diisocyanate and 5.5 g (31 mmol) of isocyanatomethyl-trimethoxysilane is quickly added to the solution. The reaction can be followed by increasing the viscosity of the solution and by means of FT-IR. The solution is stirred for a further 1 h at 60 ° C. The implementation is complete when the NCO band is no longer visible in FI-IR. Then the THF is removed in vacuo. A colorless polymer with a softening range of 90-100 ° C. and a viscosity of 80 Pas at 90 ° C. is obtained.

Example 2:

400 g (110 mmol) of α, ω-bisaminpropylpolydimethylsiloxane with an average molecular weight of 3800 are at 80 ° C in 0.5 h Vacuum ^' heated, cooled to 60 ° C and then mixed with 550 ml of dry THF. A mixture of 24.0 g (96 mmol) of diphenylmethyl-4, 4-diisocyanate and 6.4 g (31 mmol) of isocyanatopropyltrimethoxysilane in 50 ml of dry THF is quickly added to the solution. The reaction can be followed by increasing the viscosity of the solution and by means of FT-IR. The solution is stirred for a further 1 h at 60 ° C. The implementation is complete when the NCO band is no longer visible in FI-IR. The THF is then removed in vacuo. A colorless to slightly yellowish polymer with a softening range of 145-155 ° C. and a viscosity of 45 Pas at 150 ° C. is obtained. _

The adhesion and tensile expansion tests are carried out as described in Example 1.

Example 3:

500 g (300 mmol) of α, ω-bisaminpropylpolydimethylsiloxane with an average molecular weight of 1600 are heated in a vacuum at 80 ° C. for 0.5 h, cooled to 60 ° C. and then mixed with 400 ml of dry THF. A mixture of 55.6 g (260 mmol) of isophorone diisocyanate and 18.0 g (88 mmol) of isocyanatopropyltrimethoxysilane is quickly metered into the solution. The reaction can be followed by increasing the viscosity of the solution and by means of FT-IR. The solution is further stirred for l ^'h at 60 ° C. The implementation is complete when the NCO band is no longer visible in FI-IR. The THF is then removed in vacuo. A colorless polymer with a softening range of 80-90 ° C. and a viscosity of 85 Pas at 90 ° C. is obtained. The adhesion and tensile expansion tests are carried out as described in Example 1.

Adhesion: glass (+), aluminum (O), PVC (-) tear strength: 3.10 MPas, elongation at break: 178%, 100% modulus: 1.46 MPas, hardness: 48 ShoreA.

Example 4:

600 g (85 mmol) α, ω-bisaminpropylpolydimethylsiloxan with an average molecular weight of 6860 are at 80 ° C for 0.5 h in Heated vacuum, cooled to 60 ° C and then mixed with 600 ml of dry THF. To the solution a mixture of 15.0 g (70 mmol) of isophorone diisocyanate ^'and 6.8 g is rapidly (33 mmol)

Isocyanatopropyltrimethoxysilan metered. The reaction can be followed by increasing the viscosity of the solution and by means of FT-IR. The solution is stirred for a further 1 h at 60 ° C. The

Implementation is complete when no more NCO bands are visible in FI-IR. The THF is then removed in vacuo.

A colorless polymer with a softening range of 75-85 ° C. and a viscosity of 55 Pas at 80 ° C. is obtained.

Adhesion: glass (+), aluminum (0), PVC (-)

Tensile strength: 1.68 MPas, elongation at break: 263%,

100% modulus: 0.86 MPas, hardness: 21 ShoreA.

Example 5:

400 g (110 mmol) of α, ω-bisaminpropylpolydimethylsiloxane with an average molecular weight of 3800 are baked at 80 ° C for 0.5 h in a vacuum, cooled to 60 ° C and then with 600 ml of dry THF and 2.0 g (22 mmol ) 1, 4-butanediol and 200 ppm dibutyltin dilaurate added. A mixture of 24.5 g (115 mmol) of isophorone diisocyanate and 7.8 g (38 mmol) of isocyanatopropyltrimethoxysilane is quickly added to the solution. The reaction can be followed by increasing the viscosity of the solution and by means of FT-IR. The solution is stirred an additional 1 h at 60 ° C. The implementation is complete when the NCO band is no longer visible in FI-IR. The THF is then removed in vacuo. A colorless polymer which is solid at room temperature and has a softening range of 90-100 ° C. and a viscosity of 65 Pas at 95 ° C. is obtained.

Adhesion: glass (+), aluminum (+), PVC (-) tear strength: 3.43 MPas, elongation at break: 473%, 100% modulus: 1.21 MPas, hardness: 45 ShoreA.

Example 6: In a twin-shaft kneader from Collin, Ebersberg, with 4 heating zones, the aminoproyl-terminated silicone oil was metered into the first heating zone under a nitrogen atmosphere. The temperature profile of the heating zones was programmed as follows: Zone 1 30 ° C, Zone 2 90 ° C, Zone 3 150 ° C and Zone 4 140 ° C. Speed: 90 min ^"1 educt metering: 7.6 g / min (2 mmol / min) α, ω-bisaminpropylpolydimethylsiloxane

(Mn = 3800)

356 mg / min (1.6 mmol / min) isophorone diisocyanate

100 mg / min (0.5 mmol / min) isocyanatopropyltrimethoxysilane

A mixture of isophorone diisocyanate and isocyanatopropyltrimethoxysilane - previously saturated with nitrogen - is fed in at 40 ° C at the beginning of the extruder screw using a metering pump. The isocyanate mixture is then heated to 90 ° C. in the second heating zone and the reaction extruder is rinsed with the two isocyanates at the temperatures set above for a few minutes. At 90 ° C, the α, ω-bisaminpropylpolydimethylsiloxane - which was previously heated in a vacuum at 80 ° C and saturated with nitrogen for 0.5 h - is metered in via a metering pump and the mixture in the extruder is heated to 150 ° C and thus completely implemented. The product is extruded through an outlet nozzle at 140 ° C and then cooled in a stream of nitrogen. After approx. 30 minutes, the reaction and the product quality have settled evenly. The preliminary product obtained is discarded. A colorless polymer is then obtained with a softening range of 80-90 ° C. and a viscosity of 75 Pas at 90 ° C. The product is granulated for easier handling.

The adhesion and tensile strain tests are carried out as described in Example 1.

Adhesion: glass (+), aluminum (0), PVC (-) tear strength: 2.75 MPas, elongation at break: 243%, 100% modulus: 1.62 MPas, hardness: 42 ShoreA

Example 7: To those according to Example 1 (Example 7a), 3 (Example 7b) and 4

(Example 7c) polymers produced after the reaction

4.0 wt.% Aminoethylaminopropyltrimethoxysllan added and then the THF slowly evaporated in vacuo at 25 ° C.

7a) has a softening range of 80 - 90 ° C and one

Viscosity of 60 Pas at 90 ° C.

7b) has a softening range of 85 - 95 ° C and one

Viscosity of 90 Pas at 90 ° C.

7c) has a softening range of 75 - .85 ° C and a

Viscosity of 35 Pas at 90 ° C.

The adhesion and tensile expansion tests are carried out as described in Example 1 and the results are summarized in Table 1.

Example 8: "

To the polymer prepared according to Example 4 according to the

Reaction 20% by weight silicone resin (MQ) was added and then - the THF was removed in vacuo at 60-90 ° C.

The colorless product has a softening range of 80 - 90

° C and a viscosity of 35 Pas at 90 ° C.

Example 9:

To the polymer prepared according to Example 3 after

Reaction 20% by weight of a trimethylsilyl-terminated silicone oil with a. Added viscosity of 100 mPas and then stripped the THF in vacuo at 60 - 90 ° C.

The colorless, slightly cloudy product has a softening range of 75 - 85 ° C and a viscosity of 20 Pas at 90 ° C.

The adhesion and tensile expansion tests are carried out as described in Example 1 and the results are summarized in Table 1. Table 1: Properties of moisture-curing compositions according to Examples 1-9

Claims

claims

1 . Moisture-crosslinkable compositions containing (A) 100 parts by weight of silane-terminated polydiorganosiloxane-urea / urethane copolymer of the general formula 1

( 1 ) ,

wherein R is a monovalent hydrocarbon radical with 1 to 20, optionally substituted by fluorine or chlorine

-O- can be replaced, A is an oxygen atom or an amino group -NR ^X -, R is hydrogen or an alkyl radical having 1 to 10

Carbon atoms, Y one optionally substituted by fluorine or chlorine

Hydrocarbon radical having from 1 to ^'20 carbon atoms, D is optionally substituted by fluorine, chlorine, C ^ alkyl or -CG

C 1 -C 6 -alkyl ester substituted alkylene radical with 1 to 700

Carbon atoms in which are not adjacent

Methylene units by groups -0-, -COO-, -OCO-, or -

OCOO-, can be replaced B is a radical of the general formula 2

-Z-Si ⁽ R ^l) _m ⁽ R- ⁾ ₃ -m (2),

Z is an alkylene radical with 1 to 10 carbon atoms,

R is a monovalent hydrocarbon radical with 1 to 12 carbon atoms, optionally substituted by fluorine or chlorine,

R ^Λ a moisture-reactive radical which is selected from C; ι_-C4-alkoxy, C _] _-C o-acyl, Ci-Cg-alkylaminooxy and

C _] _-Cg-alkyloxy residues,

W is a radical B or hydrogen, m is 0, 1 or 2, n is an integer from 1 to 300, a is an integer from at least 1, b is 0 or an integer from 1 to 30, c is an integer from 1 to 30 and d represent the value 0 or 1, with the proviso that the composition of the units is selected such that the copolymer has a melting point in the range from 30 to 200 ° C. and

(B) 0.1 to 20 parts by weight of silane of the general formula 3

Ω- (CH ₂ ) _e -Si (R ² ) ₃ _f (CH ₃ ) f (3)

where Ω is a group selected from -NHR ³ ,

-NR ³ - (CH ₂ ) g -NHR ³ , acrylic, methacrylic, OCN, -SH, glycidoxy or chlorine radical, R ^{3 is} hydrogen or an optionally halogen-substituted

Cl-ig-hydrocarbon radical,

R ^{2 is} a methoxy or ethoxy group, e is 1 or 3 f is 0 or 1 and g is 1 to 10.

2. Moisture-crosslinkable compositions according to Claim 1, in which the copolymers (A) are end groups of the general formula 8

-CH ₂ -Si (R ¹ ) _m (R ^x ) ₃ _ _m (8)

have, wherein R ¹ , R ^xx and have the meanings given in claim 1.

3. Moisture-crosslinkable compositions according to claim 1 or 2, in which the polydiorganosiloxane sections in the copolymer (Ä) have a molecular weight Mw of 500 to 30,000.

4. Moisture-crosslinkable compositions according to claims 1 to 3, in which R is methyl or phenyl.

5. Moisture-crosslinkable compositions according to claims 1 to 4, in which A represents an amino group.

6. Moisture- ^{crosslinkable} compositions according to claims 1 to 5, in which R ^{1Λ is} a methoxy or ethoxy radical. _^

7. Moisture-crosslinkable compositions according to claims 1 to 6, in which Ω denotes a group which is selected from a radical -NHR ³ , -NR ³ - (CH ₂ ) _g -NHR ³ and glycidoxy radical.

8. Use of the composition according to claims 1 to 8 as a one-component, moisture-crosslinking hot melt adhesive via silane end groups.